NTP即Network Time Protocol（网络时间协议），是一个互联网协议，用于同步计算机之间的系统时钟。timedatectl程序可以自动同步Linux系统时钟到使用NTP的远程服务器

命令timedatectl的使用。

查看帮助命令。

timedatectl -h

timedatectl [OPTIONS...] COMMAND ...

Query or change system time and date settings.

Commands:
  status                   Show current time settings
  show                     Show properties of systemd-timedated
  set-time TIME            Set system time
  set-timezone ZONE        Set system time zone
  list-timezones           Show known time zones
  set-local-rtc BOOL       Control whether RTC is in local time
  set-ntp BOOL             Enable or disable network time synchronization

systemd-timesyncd Commands:
  timesync-status          Show status of systemd-timesyncd
  show-timesync            Show properties of systemd-timesyncd

Options:
  -h --help                Show this help message
     --version             Show package version
     --no-pager            Do not pipe output into a pager
     --no-ask-password     Do not prompt for password
  -H --host=[USER@]HOST    Operate on remote host
  -M --machine=CONTAINER   Operate on local container
     --adjust-system-clock Adjust system clock when changing local RTC mode
     --monitor             Monitor status of systemd-timesyncd
  -p --property=NAME       Show only properties by this name
  -a --all                 Show all properties, including empty ones
     --value               When showing properties, only print the value

See the timedatectl(1) man page for details.

查看当前状态。

songyangji@SongyangJi-Ubuntu-DeskStop:~$ timedatectl status
               Local time: 日 2021-04-18 18:24:40 CST
           Universal time: 日 2021-04-18 10:24:40 UTC
                 RTC time: 日 2021-04-18 10:24:37    
                Time zone: Asia/Shanghai (CST, +0800)
System clock synchronized: no                        
              NTP service: inactive                  
          RTC in local TZ: no    

开启/关闭时间同步

timedatectl set-ntp true／false